i8259 is an ISA device (or at least, depends on the ISA infrastructure to
register its ioport); and the ISA bus is supplied by piix4. Later patches
make this dependency explicit.
Use qemu_irq_proxy() to stop the cycle by adding an extra layer of
indirection.
Signed-off-by: Avi Kivity <a...@redhat.com>
---
hw/mips_malta.c | 20 +++++++++++++++-----
1 files changed, 15 insertions(+), 5 deletions(-)
diff --git a/hw/mips_malta.c b/hw/mips_malta.c
index 0110daa..1ec1228 100644
--- a/hw/mips_malta.c
+++ b/hw/mips_malta.c
@@ -778,7 +778,7 @@ void mips_malta_init (ram_addr_t ram_size,
int64_t kernel_entry;
PCIBus *pci_bus;
CPUState *env;
- qemu_irq *i8259;
+ qemu_irq *i8259 = NULL, *isa_irq;
qemu_irq *cpu_exit_irq;
int piix4_devfn;
i2c_bus *smbus;
@@ -928,17 +928,27 @@ void mips_malta_init (ram_addr_t ram_size,
cpu_mips_irq_init_cpu(env);
cpu_mips_clock_init(env);
- /* Interrupt controller */
- /* The 8259 is attached to the MIPS CPU INT0 pin, ie interrupt 2 */
- i8259 = i8259_init(env->irq[2]);
+ /*
+ * We have a circular dependency problem: pci_bus depends on isa_irq,
+ * isa_irq is provided by i8259, i8259 depends on ISA, ISA depends
+ * on piix4, and piix4 depends on pci_bus. To stop the cycle we have
+ * qemu_irq_proxy() adds an extra bit of indirection, allowing us
+ * to resolve the isa_irq -> i8259 dependency after i8259 is initialized.
+ */
+ isa_irq = qemu_irq_proxy(&i8259, 16);
/* Northbridge */
- pci_bus = gt64120_register(i8259);
+ pci_bus = gt64120_register(isa_irq);
/* Southbridge */
ide_drive_get(hd, MAX_IDE_BUS);
piix4_devfn = piix4_init(pci_bus, 80);
+
+ /* Interrupt controller */
+ /* The 8259 is attached to the MIPS CPU INT0 pin, ie interrupt 2 */
+ i8259 = i8259_init(env->irq[2]);
+
isa_bus_irqs(i8259);
pci_piix4_ide_init(pci_bus, hd, piix4_devfn + 1);
usb_uhci_piix4_init(pci_bus, piix4_devfn + 2);
--
1.7.6.3
